燕麦镰刀菌GD-2毒素对野燕麦的除草活性研究

Herbicidal Activity of Toxin from Fusarium avenaceum GD-2 against Wild Oats（Avena fatua L.）

评价了燕麦镰刀菌GD-2毒素对野燕麦的除草活性潜力。毒素对野燕麦种子萌发抑制试验表明,当毒素浓度达到5 mg/mL时,对野燕麦种子的萌发抑制效果达77.54%,在相同浓度下,对野燕麦种子胚根的抑制效果高于对胚芽的抑制效果。在温室条件下,毒素处理野燕麦植株后,各个不同处理野燕麦株高和地上部鲜重明显减少,然而,各处理间没有明显差异。用石油醚、氯仿、乙酸乙酯和正丁醇依次萃取燕麦镰刀菌发酵滤液并获得粗提物,其中正丁醇浸提物（5 mg/mL）在离体叶片实验中效果优于其他有机溶剂粗提物。此外,在毒素对10种植物的敏感性实验中,其中稗草和藜表现对燕麦镰刀菌毒素敏感。从燕麦镰刀菌中分离出3个除草活性化合物,且具有相同的紫外吸收峰。当前结果表明燕麦镰刀菌产生的毒素具有开发成为防除野燕麦生物源除草剂的潜力。

The herbicidal activity potential of toxin from Fusarium avenaceum GD-2 was evaluated against wild oats（Avena fatua L.） in this study.The toxin was assayed in vitro to evaluate its inhibition against seed germination of A.fatua.The toxin of F.avenaceum GD-2 was shown to have an inhibitory effect of around 77.54% at 5 mg / mL against germination of A.fatua seeds.The inhibitory effect shown by the toxins against radicle had higher activity than plumule under the same concentration.The toxin of F.avenaceum GD-2 significantly diminished the plant length the part on the ground with various treatments when treated with the toxin under greenhouse conditions.However,there were no significantly different reductions in plant length and the weed fresh weight with different treatments.In detached leaf injection bioassay,the toxic metabolite was characterized after the culture filtrates crude extraction with petroleum ether,chloroform,ethyl acetate and n-butanol.The residues left after solvent evaporation were evaluated separately for their toxicity against the target weed.Residue（5 mg / mL） obtained from n-butanol fraction showed the highest toxic activity when compared with others.Moreover,a host range experiments on the sensitivity of 10 plant species revealed that barnyard grasses and goosefeet were more sensitive to the toxin of the culture filtrate.Three herbicidal active compounds were isolated and purified from cultural filtrate with the same UV absorption peak.The recent results showed potential for the development of the toxins produced by F.avenaceum GD-2 as a bio-herbicidal source to control and eliminate A.fatua weed.